"We are delighted to agree this deal to acquire what is already one of the top clubs in Europe," Mr Abramovich said.

"We have the resources and ambition to achieve even more given the huge potential of this great club."

Mr Abramovich is one of the major shareholders in Sibneft, one of Russia's largest oil companies, and "a keen follower of sport and international football," a statement said.

Mr Abramovich also has significant interests in Russia's aluminium industry, and until recently owned a sizeable stake in Russian airline Aeroflot - the sale of which may have funded the Chelsea buyout.

KEN BATES

Self-made millionaire from ready-mix concrete

Bought a struggling Chelsea for £1 in 1982

In 1985 he wanted to install electric fences to control crowd trouble at
Stamford Bridge

In 1991 he ran into controversy when it was alleged Chelsea made illegal
payments to players - the club was fined £105,000

The TV interests were significant, "as in the modern game today TV rights are what it's all about," he said.

"Football has been in terrible trouble in this country recently - it's clocked up huge debts and the transfer market has collapsed," he added.

"I think what this could signal is the arrival of overseas sugar daddies.

"If this is the start of the super-rich invaders it'll be very, very interesting to see how the fans react to it."